Stitch-forming mechanism for sewing machines



Nov. 4, 1930.

W. MYERS STITCH FORMING MECHANISM FOR SEWING MACHINES Filed July 3. 1929 3 Sheets-Sheet .L

gwwmlov Billie/- Myers Nov. 4, 1930.

W. MYERS STITCH FORMING MECHANISM FOR SEWING MACHINES Filed July 3, 1929 3 Sheets-Sheet. 2.

womb Walfier Myers Nov. 4, 1930. w. MYERS STITCH FORMING MECHANISM FOR SEWING MACHINES Filed July 3, 1929 3 SheetsSheet. 5

Walt er M ers awed/wag Patented Nov. 4, 1930 UNITED STATES PAT ENT' OFF-ICE WALTER MYERS, F BRIDGEPORT, CONNECTICUT, ASSIGNOB TO THE SIN GER MANU- FACTURING COMPANY, OF ELIZABETH, N13? JERSEY, .4 3.

JERSEY COEEEOBATION OF NEW" STITCH-FORMING MECHANISM FDR- SE'WING MACHINES Application filed 'July 3, 1929. Serial No. 375,615.

This invention relates toimprovements in stitch-forming mechanisms for sewing machines and While designed more particularly for the embroidering type of sewing ma chines, it may be employed in any sewin machines in Which the needles receive latera movements in addition to their endwise, work-penetrating reciprocations.

The primary object of this invention is to 10 increase the possible speed of efficient oper ation of a sewing machine having a laterally vibratile needle. To the attainment of this object, the present invention comprehends the provision of improved needle-vibrating mechanism; improved actuating mechanism for the loop-taker which cooperates with the needle in the formation of stitches, and improved compensating means for insuring loop-seizing relationship between the needle and the loop-taker during reoiprocations of the needle in different paths.

In a preferred embodiment of the invention, the needle-carrying bar is journaled for endwise reciprocation in a vibratory frame operated from a rock-shaft having an arm connected with one end of a link of which the opposite end is shiftable, under manual control during the operation of the 8 machine, in a segment provided on a camactuated rock-lever fulcrumed upon the machine frame. The fulcrum of this rock-lever is shiftable into positions in one of which the zero path of non-vibration of the needle 5 is central of its vibratory movements, while in the other position the needle is vibratable only at one side of its zero path, although the extreme limits of throw of the needle are substantially the same in both cases. The 40 link which is shiftable with respect to the rock-lever segment for controlling the amplitude of the needle vibration is suitably connected with a treadle or knee-shift for this purpose.

The loop-taker which cooperates with the needle in the formation of lock-stitches is of the rotary hook type, being carried by a horizontally disposed shaft beneath the cloth-plate. This shaft is gear-driven, through a vertically disposed intermediate shaft, from a main actuating shaft journaled in the machine bracket-arm. The loop-taker shaft is journaled in bearings provided in a horizontally vibratory frame pivotally supported at one endupon said vertical intermediate shaft and slidably supported adjacent to the loop-taker in a suitable guideway.

In order to insure loop-seizing relationship between the loop-taker and the needle during lateral vibrations of the latter, the loop-taker shaft supporting frame is vibrated in timed relation with the needle-vi brations. However, as the loop-taker eificiently seizes needle-thread loops up to a predetermined range of vibration of the needle, withoutcompensatin g movements of the loop-taker, said vibratory movements of the loop-taker shaft supporting frame are only initiated for-vibrations of the needle beyond said predetermined range. To this end, said loop-taker shaft frame is so connected with the needle-vibrating mechanism as tobe'inoper'ative for needle-vibrations within a predetermined range, but is rendered operative through lost motion connections with the needle-vibration controlling means for needle vibrations beyond said ran e. r

Preferably, the present improvement also comprehends the provision of means for 0011- veniently adjusting the needle-vibrating mechanism, independently of the treadle control therefor, and for maintaining theselected extent of vibration without further attention by the operator. Inasmuch as the rotary loop-taker is bodily shifted during only the wider lateral movements of the needle and then only to the extent necessary to insure loop-seizing relationship with the needle, said bodily movements of the loop-taker when initiated, may be relatively short compared with the needle-vibrations. ()bviously therefore, the present construction provides for a very material increase in the possible speed of operation of the machine.

In the accompanying drawings, Fig. l is a longitudinal section of a sewing machine containing a preferred embodiment of the present improvement. "Fig; 2 represents a i IOU bottom plan View of the machine. Fig. 3 standard 2. The counter-shaft 33 carries a is a sectional view substantially on the line 33 of Fig. 1 looking toward the needle end of the machine. Fig. 4 is a section substantially on the same line as Fig. 3, but viewed in the opposite direction. Fig. 5 is a face View of the needle-throw adjusting device. Fig. 6 is a detail sectional view of one of the stops of said adjusting device. Fig. 7 is a perspective view of the bobbin-case stop arm. Figs. 8 and 9 are diagrammatic views illustrating the throw of the needle-actuating rock-shaft in the different positions of the axis of the rock-shaft actuating segmentlever.

Referring to the drawings, the. sewing machine comprises a cloth-plate 1, from which rises the hollow standard 2 of a tubular, overhanging bracket-arm 3 terminating in a head 1. Journaled in the bracket-arm3 is a main actuating shaft5, carrying at one end a beltpulley 6 and atits opposite end a crank-disk 7 connected by the usual link 8 with a needle bar 9. The needle-bar 9 carries at its lower end a needle 10 and is journaled for endwise reciprocation in bearings provided in a vibratory frame 11 supported upon a fulcrumpin 12 for swinging movements in directions substantially transverse to the axis of rotation of the main-shaft 5, i. e., substantially transverse to the longitudinal direction of the cloth-plate 1. The fulcrum-pin 12 preferably has a reduced extension 13 which is eccentric to the journal-axis of the frame 11 and is secured upon the head 1 by means of a screw 14-, thereby providing means permitting adjustment of the needle position.

The presser-foot 1.5 and its supporting means employed in the present machine is substantially the same as disclosed in my prior U. S. Patent No. 1135,959, April 13, 1915, to which reference may be had for fur ther details of its construction. The throatplate 16, provided with the needle-slot 17, is sustained by a supporting plate 18 suitably secured upon the cloth-plate 1, said throatplate being latched by a bifurcated plate 19 secured upon the underside of a removable slide-plate 20.

Suitably connected with the nee lle-bar frame 11 is a crank-arm 21 upon the forward end of a rock-shaft 22, journaled in the machine bracket-arm below and in parallel relationship with the main-shaft 5. At its rearward end, the rock-shaft 22 fixedly carries an angle-lever of which one arm 23 is grooved to provide a segmental guideway 24 andthe other arm 25 ofwhich lever is connected by a link 26 with a slide-block 27 shiftably disposed in a segmental guideway 28 provided in an arm 29 of an actuating lever. The other arm 30 of this actuating lever terminates in a fork 31 which straddles a cam 32 upon a counter shaft 33 journaled in a bearing lug 34 provided within the machine gear-Wheel 35 driven by a pinion 36 upon the main shaft 5 to rotate the counter-shaft at one half the speed of the main shaft.

It will be understood that upon rotation of the counter-shaft 33, the cam 32 imparts rocking movements of constant amplitude to the actuating lever 29, 30 and that these rocking movements are transmitted to the rockshaft 22 through the link 26 and lever-arm 25 in any position of the slide-block 27 beyond its neutral position, i. e., beyond the position in which the pivotal connection of the slideblock with the link 26 coincides with the pivotal axis of the lever 29, 30.

In order to shift the slide-block 27 in its guideway 28, under treadle control, the link 26 is pivotally connected with an intermediate link 37 of which the lower end is suitably apertured to loosely receive a stud-screw 38 upon the free end of an arm 39. The arm 39 is integral with a yoke 40 suitably secured upon a fulerinn-shaft d1 of which the opposite ends are journaled in bearing a 'iertures provided in the parallel ribs, as 42, depending from the cloth-plate 1. The yoke 40 is formed with an apertured boss 43 receiving a rod 14 secured by a set-screw 15, said rod 1% being operable from a treadle or knee shift in any suitable manner to impart endwise movements to the link 37.

In addition to the treadle-control of the lateral throw of the needle and in combination therewith, means are provided for adjustably limiting the extent of throw of the needle and also for selectively obtaining a uniform extent of needle-vibration during continuous operation of the machine. To this end, the arm 39 is pivotally connected with a twisted link 16 similarly joined to an arm 47 of a lever having its other arm 4-8 provided with an arcuate slot 49 of which the center of curvature coincides with the axis of the lever 47, 48. The lever 17, 48 is fixed upon a short shaft 50 ournaled in a bushing 51 adjustably fixed in an aperture in the standard 2 by means of a screw 52.

Preferably integral with the bushing 51 a segment-plate 53 disposed at the outside of the standard 2 and partly under the bracketarm 3. This segment-plate 53 provided with an arcuate slot 54 which is T-shaped in cross-section and slidingly receives a headed stop-pin 55 secured in adjusted position in the slot 54 by means of a stop-nut 56 bearing upon a washer 57. Spaced from the stop-nut 56 and adjustably disposed in the t 5 1- is the pin of another stop-nut 58 corresponding in structure to the previously descr'bed stop. Upon the outer end of the shaft 50 is secured the hub 59 of an arm 60 carrying at its overhanging free end a securing screw 61 adapted to engage the periphery of the segment-plate 53 to thereby provide for adjustably securing the shaft 50 against movement and consethe bushing. The bushing 90 is suitably fixed in a lug 93 within the standard 2 and affords a journal for the lower end of a vertically disposed, intermediate shaft 94 carrying a gbevel-gear 95 in mesh with a similar gear 96 fixed upon the rearward end of the looptaker shaft 7 6. At its upper end, the shaft 94 is ournaled in a bushed bearing-lug 97 within the standard 2 and carries a bevel gear 98 which is one half the size of a gear 99 upon the main shaft 5, whereby the loop-taker is rotafted twice for each rotation of the main sha t.

A lateral extension 100 of the slide-block or lug 77 has a ball-joint connection with an extensible pitman 101 similarly connected with a. crank-arm 102 of a rock-shaft 103 suitably journaled beneath the cloth-plate 1. Clamped upon the rearward end of the rockshaft 103 is a crank-arm 104 having an elongated slot 105 to which crank-arm is adjust ably secured the lower end of a link 106. At its upper end, the link 106 is pivotally connected with a slide-block 107 shiftably disposed in the segmental guideway 24 of the angle-lever 23, 25. A lateral extension 108 of the link 106 is provided with a transverse guide-groove 109 for a slide-block 110 pivotally carried by an arm 111 of an anglelever fulcrumed for rocking movements upon the adjusting shaft 50. The other arm 112 of said angle-lever fixedly carries a stud 113 which freely enters the arcuate slot 49 in the lever-arm 48. The stud 11.3 therefore constitutes a lost-motion connection between the lever-arm 48 and the lever-arm 112, the extent of play of the stud 113 within the slot 49 being adjustably limited by the end of a screw 114 threaded into the upper side of the lever-arm 48 to extend into the slot 49 lengthwise thereof. A coil-spring. 115 connects the arm 1.1.2 with the bracket-arm 3, whereby the slide-block 107 is yieldingly held against a shouldered stop 116 intersecting the guideway 24 atone end thereof.

It will be apparent from the foregoing description that the needle 10 is reciprocable in two zero positions of non-vibration, one of which is at the center and the other at one side of its path of vibratory movement. These zero positions depend upon the location of the fulcrum-axis of the segment-lever 29, 30, which location may be changed by shifting the handle 68. In either position of the fulcrum-axis of the segment-lever 29, '30, the needle may be caused to vibrate laterally while above the work by shifting the slide-block 27 to any point at one side of the segment-lever axis to an extent limited by the adjustable stop-nuts 56 and 58. The shifting of the slideblock 27 may be effected by the described connections with the treadleactuated rod 44 or may be effected by directly shifting the arm and if it is desired to uniformly maintain a definite amplitude of vibration of the needle, the arm 60 may be secured against movement by clamping the screw 61 against the periphery of the stationary segment-plate 53.

By properly timing the reciprocations of the needle 10 with the rotations of the looptaker 73, the needle may have a substantial range of lateral vibratory movementin a fixed position of the loop-taker axis without occasioning skipping of stitches. In the present instance a safe range of lateral movement of the needle is approximately of an inch, but this range will of course vary in different constructions of the parts. In the present construction, the loop-taker axis remains fixed for any needle-vibrations within said safe range because the pivotal axis of the slide-block 107, under the influence of the spring 115, normally coincides sub-- stantially with the axis of the rock-shaft 22 and consequently the link 106 is normally unresponsive to any rocking movements imparted to the lever 23, 25 by the segment; lever 29, 30. This normal position of the slide-block 107 remains unchanged during a predetermined extent of off-center movement of the slide-block 27 in its guideway, because of the lost-motion connection between the lever-arms 48 and 112 afforded by the arcuate slot 49, it being understood that the arm 48 is moved downwardly as the slide-block 27 is shifted off center with respect to the axis of the segment-lever 29, 30, whereby the end of the screw 114 approaches the stud 113 which normally engages the lower end of the slot 49. When the slide block 27 is shifted a suiiicient extent to cause the screw 114 to engage the stud 113, the manually initiated movement of the lever 47, 48 is transmitted to the lever 111, 112. consequently shifting the slide-block 107 off the axis of the rock-shaft 22 and thereby causing actuation of the link 106 to laterally vibrate the loop-taker shaft frame 79 to an extent which may be adjustably determined by means of the adjustable connection between the lower end of the link 106 and the rock-shaft crank-arm 104. The reciprocatory movements of the link 106 are however not transmitted to the lever 111, 112 because of the link-extension groove 109, as will be readily understood.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, an endwise reciprocatory needle, a loop-taker cooperating with said needle in the formation of stitches, mechanism for vibrating the needle laterally, and compensating mechanism for insuring cooperative relation between the loop-taker and the needle during lateral vibrations of the latter, which compensating mechanism is ineffective during vibrations of the needle from its position of non-vibration to a predetermined extent of vibration and is rendered eilective for vibrations of the needle beyond said predetermined extent.

2., In a sewing machine, an endwise reciprocatory needle, a loop-taker cooperating with said needle in the formation of stitches, mechanism for ibrating the needle laterally, and loop-taker compensating mechanism which ineliiective during vibrations of the needle from its position of non-vibration to a mined ercten't'o'f lateral vibration and is rendered elifecthv or ribrations of the needle beyond said predetermined extent.

3. In a sewingvmachine, an endwise reciprocatory needle, a loop-taker cooperating with said needle in the formation of stitches, mechanism for vibrating the needle laterally, and compensating mechanism comprising means for bodily vibratingthe loop-taker to insure seizure of needle-thread loops by i said loop-taker during lateral vibrations of the needle,-said loop-taker vibrating mecha nism being inefiective during vibrations of the needle from its position of non-vibration to apredetermined extent of lateral vibration and brought into effective action for vibrations of the needle beyond said predetermined extent. 3

In a sewing machine, an endwise reciprocatory needle, mechanism for laterally vibrating said needle, a loop-talrer adapted to seize;.needlethread loops up to a predetermined extent of lateral vibration of the needle in the formation of stitches, compensating mechanism brought into efl'ective action beyond said predetermined extent of needlevibration to maintain loop-seizing relationship between the needle and the loop-taker, and means for adj ustably predetermining the extent of needlewibration atwhich the looptalzer compensating mechanism is brought into eilective action.

in asewing. machine, an endwise reciprocatory needle, mechanism for laterally vibrating said needle, a loop-taker adapted to seize needle-thread loops up to a predetermined extent of lateral vibration'of the needle in the formation of stitches, means formanually controlling the extent of needle vibration, and compensating mechanism brought into effective action by said manually controlled means after the needle has reached said predetermined extent of lateral Vibution to maintain loop-seizing relationship between the needle and the loop-taker.

6. In a sewing machine, an endwise reciprocatory and laterally vibratory needle, means for selectively determining zero positions of non-vibration of the needle at the center and at one side of its range of lateral movement, a loop-taker cooperating with said needle in the formation of stitches, and means forvlaterally vibrating the loop-taker to insure loop-seizing relationship between said loop-taker and the needle in vibrations of the latter across its central zeroposition at one side of its other zeroposition.

7. In a sewing machine, aniendwise-reciprocatory needle, a loop-taker cooperating with said needle in the iormationof stitches, mechanism for laterally vibrating said needle, manually controlled means forzdctermining the amplitude of lateral'vibration of the needle, and mechanism having a lostinotion connection with said manually controlled means for bodily shifting said loop-taker in timed relation with and at a less distance than he needle vibrations to insure seizure by the cop-taker of :the thread loops presented by he needle while reciprocating indifferent paths.

8. In a sewing machine, an endwise reciprocatory needle, a loop-taker cooperating I with said needle in the formation of stitches,

mechanism for laterally V1b1&t-1I1g-83.1(l=.1168+ 1 clle, means manually controllable during :ihe operation of the machine for determining the amplitude of lateral vibration of theneedle, compensating mechanism for maintaining loop-seizing relationship between the needle and the loop-taker during lateral vibrations of the needle, and a lost motion connection between said compensating mechanism and said manually controlled means for bringing said compensating mechanisminto operation upon vibration of the needle beyond apredete-rmined extent.

9. a sewing machine, in .combin-tion, a work-support, a reciprocatory needle,.mechanish for relatively jogging :the'needle and work sustained by said work-support in the formation of zigzag stitches, a loop-taker complemental to the needle in the formation of said stitches, and comp ensati ng mechanism for .maintaining loop-seizing relationship between the needle and loop-taker duringthe rela'" 'e jogging movements ofgthe needleand work, which compensating mechanism is lireffective up to a predetermined range of said relative jogging movements andxbecomesefiective for jogging movements beyond said predetermined range.

10. In a sewingimachine, anendwise reciprocatory needle, (mechanism i'onrlaterally vibrating said needle, a loop-takeincooperating with said needle in the formation of stitches. compensating mechanism brought into micetive action beyond a predetermined amplitude of needle-vibration for maintaining loopseizing relationship between the needle and the loop-taker, andmeans forfiadjustably determining the degree of actionof said @0111- pensating mechanism with respect to theamplitnde of needle-vibration.

11. In a sewing machine,an endwise reciprocatory w needle, mechanism for laterally ribrating said needle, a loop-takercooperating withsaid needlein the formation ofstitelies, compensating.inechanism brought into-efi ective action beyond arpredetrmined amplitude lit" of needle-vibration for maintaining loop seizing relationship between the needle and the loop-taker, means for adjustably predetermining the amplitude of needle-vibration at which said compensating mechanism is brought into efiective action, and means for adjustably determining the degree of action of said compensating mechanism with respect to the amplitude of needle-vibration.

12. In a sewing machine, an endwise reciprocatory and laterally vibratory needle, means for selectively determining zero positions of non-vibration of the needle at the center and at one side of its range of lateral movement, a loop-taker cooperating with said needle in the formation of stitches, and compensating mechanism brought into effective action beyond a predetermined amplitude of needle-vibration for maintaining loop-seiz'- ing relationship between the needle and the V loop-taker in vibrations or the needle across its central Zero position and at one side of its other zero position.

18. In a sewing machine, a needle-bar, a needle carried by said needle-bar, a laterally movable frame in which said needle-bar is journaled for endwise reciprocation, a rockshaft operatively connected with said frame for imparting lateral movements thereto, means for actuating said rock-shaft, controlling mechanism for determining the extent of lateral movement imparted to said frame, a loop-taker cooperating with said needle in the formation of stitches, a guideway fixed upon and intersecting the axis of said rockshaft, a guide-block shiftable in said guideway from a position normally in substantial alinement with the axis of said rock-shaft, a slide-block shifting lever, a lost-motion connection between said needle-bar vibrating controlling mechanism and said shifting lever, and a member connected with said slideblock for imparting compensating movements to said loop-taker in positions of said slide-block out of alinement with the axis of said rock-shaft.

14. In a sewing machine having a clothplate and an arm overhanging the cloth-plate, a reciprocatory needle, a loop-taker cooperating with said needle in the formation of stitches, a rotary loop-taker actuating shaft beneath the cloth-plate, a rotary shaft journaled in said arm, an intermediate shaft operatively connecting said shafts, a loop-taker actuating shaft supporting frame journaled for vibratory movements about the axis of said intermediate shaft, and means for vibrating said frame.

15. In a sewing machine having a clothplate and an arm overhanging the clothplate, a main-shaft journaled in said arm, a needle deriving endwise reciprocations from said main-shaft, a loop-taker cooperating with said needle in the formation of stitches a rotary loop-taker carrying shaft,

an intermediate shaft having gear connections with said mainand loop-taker shafts, a loopy-taker shaft supporting frame journaled for vibratory movements about the axis of said intermediate shaft, a support for said frame adjacent the loop-taker, and means for vibrating said frame.

16. In a sewing machine, an endwise reciprocatory and laterally vibratory needle, a loop-taker cooperating with said needle in the formation of stitches, a rotary loop-taker carrying shaft, a supporting frame for said shaft journaled for vibratory movements about an axis transversely intersecting said shaft, and means for vibrating said frame a less distance than the amplitude of needlevibration to insure seizure of the threadloops presented by the needle while reciprocating in different paths.

1?. In a sewing machine, an endwise reciprocatory and laterally vibratory needle, a loop-taker cooperating with said needle in the formation of stitches, a rotary loop-taker actuating shaft, a supporting frame for said shaft, a driving shaft disposed transversely of said actuating shaft, gear connections between said shafts, means for supporting said frame for vibratory movements about the axis of said driving shaft, a rock-shaft, an operative connection between said rock-shaft and the supporting frame, and means for actuating said rock-shaft to impart bodily lateral movements to said loop-taker.

18. In a sewing machine having a clothplate and an arm overhanging the cloth-plate, a rotary actuating shaft ournaled lengthwise of said arm, a needle-carrying bar deriving endwise reciprocation from said actuating shaft, a laterally movable frame having a journal for said needle-bar, a rocleshaft journaled in said arm substantially parallel with said actuating shaft, operative connections between said rocleshaft and the needle-bar frame for imparting lateral movements to said frame, a segment-lever fulcrumcd upon said overhanging arm to rock about an L s substantially parallel with said actuat I shaft, means for rocking said segment-lever, an operative connection between said ment-lever and said rock-shaft, and means for shifting the fulcrum-axis of said segmentlever.

In testimony whereof, I have signed my name to this specification.

INALTER MY 

